This relates generally to memories, such as phase change memories, that exhibit threshold switch behavior.
Threshold switch behavior is the tendency of an element to discontinuously change its current voltage characteristics upon exceeding a threshold voltage. For example, a phase change memory may have set and reset states with different threshold voltages.
Due to variation of cells within a product, different cells may require different levels of programming current to reach the same threshold voltage. Thus, after programming, a verify may be used to ensure that the threshold voltage of each cell has been programmed above the level required to yield an adequate read window.